Pile for Foundation

ABSTRACT

The device includes the body ( 1 ), provided with a helix ( 3 ) on the bottom end, and of an ending ( 4 ) on the top part of the body ( 1 ). The diameter of the helix ( 3 ) is in the range of 1.0 to 100 times the diameter of the body ( 1 ) and/or of the least transversal dimension of the body ( 1 ). The body ( 1 ) has a closed or open profile on the cross section, with the body ( 1 ) having one profile at least. The pitch of the helix ( 3 ) is in the range of 0.1% to 90% with the pitch being linear or variable along the length of the helix and the length of the blade of the helix ( 3 ) being 5° at least of the circumference of the body ( 1 ) and the drilling base being provided with one helix ( 3 ) at least. On the bottom end, the body is provided with a pricker ( 2 ), with the pricker ( 2 ) being bevelled into one surface at least on the bottom end at the angel in the range of 90° to 0.1° towards the vertical axis of the drilling base and/or with the bottom end of the pricker ( 2 ) having a semi-spherical shape.

TECHNICAL FIELD

The device belongs in the field of building industry, i.e. in concreteterms, in launching projects to establish buildings located on piles.

BACKGROUND ART

The piles for lying foundations for buildings can be installed ascombined with earthworks. In practice, such a pile is inserted into ahole, excavated in the soil beforehand, where it is neither set norrectified however. To set and rectify the pile, the space between thepile and the hole wall must be filled e.g. with concrete. This solutionis disadvantageous due to the necessity both of excavating (drilling)works, to make a hole in the soil, and of concreting the space remaininglater after the pile insertion. Therefore, this solution is not suitablefrom economical or ecological points of view.

Another way to install piles for foundation of buildings is to drillthem into the soil. The hitherto known system of installing the piles bymeans of drilling in is known e.g. from the document PUV 2005-16435.This document describes a drilling base provided, on its bottom end,with a twist drill mounted on a shaft where the shaft is widened, on thetop edge level of the drill, into the top tube part by a conicalsection. The twist drill has equal blade areas in its whole length andis made only in the extent of 360° on the shaft. This arrangementresults in problematic setting of the drilling base in a rocky soilwhere the twist drill can be clogged with stones. Due to clogging, thebase gives up drilling deep into the soil and, if not stopped by theoperating personnel, the twist drill will be totally destructed byacting of pressure.

DISCLOSURE OF INVENTION

The main substance of the proposed technical solution is based onshaping the helix blade of the drilling base. The drilling base has onehelix blade at least. In case the drilling base is provided with onehelix only, the helix is located on the body bottom part of the drillingbase. The helix diameter is in the range of 1.0 up to 100 multiple ofthe body diameter and/or of least transversal dimension thereof. Thehelix diameter, and due to it also the surface of its blade, is constantand/or variable lengthwise. E.g. the helix diameter can increase upwardsfrom bottom. The helix pitch is given from 0.1% to 90%. Due to thisextent again, diverse variants of the drilling bases can be made forvarious kinds of soil or possibly for various types of consideredover-ground devices attached to the drilling base. The length of thehelix blade is 5° of circumference of the body at least. The harder isthe soil in the place of the drilling base installation the greater isthe weight of the over-ground device and the more intensive is theexpected influence of climatic conditions, the greater must be the helixblade length. It appears advantageous if the helix blade is longer than360°. Besides, the body can be provided with more helix blades. Thehelix pitch can be linear and/or variable.

In an alternative solution the drilling base can be provided with apricker located on the body bottom part, said pricker forming the bottomend of the drilling base. Then, the helix is located either on thedrilling base body or on the pricker. The pricker bottom end issharpened into one surface at least, namely at the angle of 90°-0.1°from the vertical axis of the drilling base. In an alternative solution,the pricker bottom can have semi-spherical end. The variant of thepricker end is chosen in accordance with the pricker diameter and withthe kind of soil into which the drilling base is installed. The prickercan be free or provided with a helix. By means of this solution, diversevariants of the drilling base can be made which differ by thehelix-to-body diameter ratio. In consequence of it, these variousdrilling bases can be utilized for diverse kind of soils (sandy, stony,or claylike ones), with the greater-helix-diameter drilling bases beingapplicable in soft soils especially, e.g. in peat.

The body can have a closed or also open profile in the perpendicularcross section. The choice of the profile, of its diameter and wallthickness is influenced by the soil kind into which the drilling basehas to be set. In some cases the body can have a polygonal shape in theperpendicular cross section. Although the drilling base, with a bodyshaped as a polygon, is difficult to set, it offers better support inthe soil against climatic influences. Equally, the body can be composedof more mutually connected profiles where open profiles can be combinedwith the closed ones and the round cross sections can be combined withpolygonal ones etc.

In some cases, the drilling base body can be shaped so that it hassmaller diameter in the bottom part than in its top part. The body canbe widened linearly and/or stepwise towards the top part. With thestepwise widening, an auxiliary helix is located on the transitionbetween parts having different diameters. The auxiliary helix enables todrill the greater-diameter body top part into the terrain. If greaterside forces are assumed to act on the drilling base, the body can beprovided with an auxiliary ring. The auxiliary ring is mounted in suchplace of the body that it will be situated beneath the soil surface withthe drilling base being drilled-in. The auxiliary ring is attached tothe drilling base body by means of a wire weave and serves for usage ina soft under-bed. For the usage in a hard rocky under-bed, the auxiliaryring is attached to the drilling base body by means of inclined felloes.Instead of being filled up with excavation soil, the space in theauxiliary ring can be possibly set in concrete afterwards.

Another possibility to improve the resistance of the drilled-in drillingbase against side forces is to make a welded wire thread around thewhole body to increase the friction between the drilling base body andthe soil in which the drilling base is located.

Alternatively, the body top ending can contain a rectifying element toenable to throw the column or the device (e.g. a solar panel) out ofparallel which are installed on the drilling base afterwards. Inpractice as a rule, several screws passing through nuts, welded toorifices in the body covering, are used as rectifying elements. Therectifying element is applied in the case the drilling base cannot bedrilled wholly vertically into the required position, especially instony soil.

Another ending can be shaped as a flange perpendicular to the drillingbase body. On the circumference, the flange has orifices for screws toattach a device which is installed on the drilling base.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary realizations of the proposed solution are described withreference on following drawings:

FIG. 1—Fundamental embodiment of the drilling base,

FIG. 2—Alternative solution with an auxiliary ring attached with felloesand with an auxiliary helix,

FIG. 3—Alternative solution with the auxiliary ring attached with a wireweave and with the auxiliary helix,

FIG. 4—Alternative solution of the small-diameter drilling base with therectification,

FIG. 5—Alternative solution of the drilling base with flange-typeending,

FIG. 6—The drilling base composed of several profiles and helices on thebody and on the pricker,

FIG. 7—The drilling base without a pricker and with several differentlylong helices on the body.

BEST MODE FOR CARRYING OUT THE INVENTION Example 1

The drilling base, made conformably to the presented technical solution,consists of the 1650 mm long body 1 with a diameter of 114 mm. The body1 is provided with the helix 3 on its bottom end. The helix 3 is locatedabove the pricker 2 which forms the bottom part of the drilling base.The blade area of the helix 3 widens from the pricker 2 towards theending 4 which forms the top part of the drilling base. In this case theblade of the helix 3 is 25 mm wide at the pricker 2 and 90 mm wide onthe top end of the helix 3. The helix 3 has the extent of 450°. Thedescribed device is evident on the FIG. 1.

Example 2

The drilling base, made in accordance with the presented technicalsolution, has total length of 4800 mm with the body bottom part 1 abeing 2600 mm long and having the diameter of 219 mm. The body top part1 b is 1800 mm long with the diameter of 360 mm. In this case, thetransition 9 is 200 mm long. On the bottom end the body 1 is providedwith the helix 3. The helix 3 is located above the pricker 2 which formsthe bottom part of the drilling base. The blade area of the helix 3widens from the pricker 2 towards the ending 4 which forms the top partof the drilling base. In this case the blade of the helix 3 is 50 mmwide at the pricker 2 and 120 mm wide on the top end of the helix 3. Thehelix 3 has the extent of 450°. The auxiliary helix 7 is located on thetransition 9. Above the transition 9 the auxiliary ring 5 is attached onthe body top part 1 b by means of the wire weave 11. On the body toppart 1 b the auxiliary ring 5 is mounted so high that it is to be foundunder the earth surface with the base being drilled in. The part of thebody 1, located under the earth surface after the base setting, isprovided with the wire 8 on its surface, said wire 8 being shaped toform a thread on the body 1 of the drilling base.

In this case the ending 4 is adapted, by means rectification brackets 6in a form of screws and nuts 12, to assemble a tracker which is used tosupport a solar panel.

The described device can be seen on the FIG. 3.

Example 3

The drilling base, according to the proposed technical solution,consists of the body 1 with the pricker 2 situated on the bottom end. Inthis case the body 1 consists of more profiles with different diametersand the bottom part of the pricker 2 is bevelled by one skew cut at theangle of 45° towards the vertical axis of the drilling base. To thepricker 2 the conical part of the body 1 is coupled on which thecylindrical part of the body 1 is located consisting of a steel tube. Onthe pricker 2 and on the conical part the helix 3 is placed. Theprolongation of the helix 3 to the pricker 2 and the form of the pricker2 facilitate to locate the drilling base into very hard soil. In thepresent case, this helix 3 has the pitch of 15% with the area of itsblade and its diameter increasing from the bottom part of the drillingbase towards the ending 4. The first helix is 540° long and its maximumdiameter equals 1.9 times the diameter of the given part of the body 1.To the cylindrical part of the body 1, further conical part or thetransition 9, are coupled respectively. On the transition 9, theauxiliary helix 7 is placed. The auxiliary helix 7 is 360° long, itspitch equals 15% and the area of its blade does not change lengthwise.The diameter of the auxiliary helix 7 equals 1.3 times the given part ofthe body 1. On the transition 9, the body top part 1 b links up whichconsists of a close steel hexagonally shaped profile.

The described solution is obvious on the FIG. 6.

Example 4

The drilling base, in accordance with the proposed technical solution,is composed of the body 1 consisting of one profile. On the bottom partof the body 1 a cone is located which is rounded on the bottom end. Inthis case, on the cone the helix 3 is located the pitch of which is 25%and the length is 360°. The area of the blade of the helix 3 and itsdiameter as well increase from the bottom part of the drilling basetowards the ending 4 in this case. In this case, the maximum diameter ofthe helix 3 is 2.8 times the diameter of the given part of the body 1.On the cylindrical part of the body 1, several other helices 3 arelocated. These further helices 3 have the length of 50° and the pitch of25%. The base drafted in such a way is suitable to support lightover-ground devices in very soft soils.

The described solution can be seen on the FIG. 7.

LIST OF REFERENCE SYMBOLS

-   1—body-   1 a—body bottom part-   1 b—body top part-   2—pricker-   3—helix-   4—ending-   5—auxiliary ring-   6—rectification bracket-   7—auxiliary helix-   8—wire-   9—transition-   10—felloe-   11—wire weave-   12—nut-   13—flange

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 18. A pile for a foundation comprising: abody having a bottom end and a top end, at least one helix provided onthe bottom end of the body, the top end including an ending; wherein thehelix has an blade having a diameter and the body has a diameter and/orleast transversal dimension, the diameter of the helix being betweenabout 1.0 to 100 times the diameter and/or least transversal dimensionof the body, and wherein the body has a cross-section and a closed oropen profile on the cross-section, the body having at least one profile,and wherein the pitch of the helix is in the range of 0.1% to 90%, withthe pitch being linear or variable in the length of the helix, andwherein the length of the blade of the helix is at least 5° of thecircumference of the body, and wherein the body has a surface which iseventually provided with a wire above the helix, with said wire beingshaped to form a thread on the surface of the body, and wherein thesurface of the body is provided with the wire below the helix, with saidwire being shaped to form a thread on the surface of the body.
 19. Apile for a foundation according to claim 18, wherein the body isprovided with a pricker on the bottom end, with the pricker beingbevelled into one surface at least on the bottom part, with an angle ofsaid bevelled surface being in the range of 90° to 0.1° toward thevertical axis of the drilling base.
 20. A pile for a foundationaccording to claim 18, wherein the body is provided with a pricker onthe bottom end, and wherein the bottom part of the pricker has asemi-spherical shape.
 21. A pile for a foundation according to claim 18,wherein the pile is provided with an auxiliary ring on the top end ofthe body below the ending.
 22. A pile for a foundation according toclaim 18, wherein the ending is provided with a rectification bracket.23. A pile for a foundation according to claim 22, wherein therectification bracket is shaped as a nut.
 24. A pile for a foundationaccording to claim 18, wherein the ending is shaped as a tube.
 25. Apile for a foundation according to claim 18, wherein the ending isshaped as a flange.
 26. A pile for a foundation according to claim 18,wherein the bottom end of the body has a smaller diameter than the topend of the body, and wherein an auxiliary helix is located on atransition between the bottom end and the top end.
 27. A pile for afoundation according to claim 19, wherein an auxiliary ring is providedon the body top part below the ending.
 28. A pile for a foundationaccording to claim 19, wherein the ending is provided with arectification bracket.
 29. A pile for a foundation according to claim28, wherein the rectification bracket is shaped as a nut.
 30. A pile fora foundation according to claim 19, wherein the ending is shaped as atube.
 31. A pile for a foundation according to claim 9, wherein theending is shaped as a flange.
 32. A pile for a foundation according toclaim 19, wherein the bottom end of the body has a smaller diameter thana top end of the body, and further including an auxiliary helix locatedon a transition between the bottom end and the top end.